The present invention relates generally to an imaging detector assembly, and, more particularly to a field testable imaging detector assembly for use in computed tomography applications.
Computed tomography has been utilized for a wide variety of imaging applications. One such category of applications is comprised of medical imaging. Although it is known that computed tomography may take on a wide variety of configurations within the medical industry, it commonly is based on the transmission of low energy rays through a body structure. These low energy rays are subsequently received and processed to formulate an image, often three-dimensional, of the body structure that can by analyzed by clinicians as a diagnostic aid.
The reception of the low energy rays, such as gamma rays or x-rays, is often accomplished through the use of a device referred to as a detector assembly. The detector assembly is typically comprised of a plurality of structures working in concert to receive and process the incoming energy rays after they have passed through the body structure. A collimator is an element often found in a detector assembly that is used to limit the direction of photons as they approach the scintillator element. The collimator is commonly used to control resolution or field of view. Their primary purpose, in a detector assembly, however, is to control the photons impinging on the scintillator element.
The scintillator element, in turn, is commonly a material with the ability to absorb the photons and convert their energy into visible light. This allows the low energy rays received by the scintillator detector to be converted into useful information. Scintillator elements may come in a wide variety of forms and may be adapted to receive a wide variety of incoming rays. The light produced by the scintillator element is commonly processed by way of a device such as a light sensitive photodiode which converts the light from the scintillator element into an amplified electronic signal. In this fashion, the information from the scintillator detector can be easily transferred, converted, and processed by electronic modules to facilitate viewing and manipulation by clinicians.
Finally detector assemblies are currently tested using x-ray excitation. In such tests x-rays are directed at the detector assembly to produce a response that can be evaluated. X-ray source equipment in field installed imaging systems, however, is often not suitable for proper detector testing procedures. It is often impossible, within field installed imaging systems, for an x-ray source to target specific regions of the detector assembly in order to properly run diagnostic procedures. Safety considerations, for example, prevent the remote triggering of x-rays from a remote location such as a manufacturers test of field equipment. Furthermore, prior to installation into the imaging system, an x-ray source may not even be available to test the detector assembly. Recalibration during a scan series in third generation CT systems is not available using existing detector assemblies since the patient may be blocking all or a portion of the detector assembly. In such situations, the patient is commonly required to be removed from the imaging system in order for recalibration to be effectuated. This increases scan-time, expense, and complexity of operation of existing imaging systems.
It would, however, be highly desirable to have a detector assembly that was suitable for field-testing without the need for x-ray generation. Similarly, it would be highly desirable to have an imaging system with a detector assembly that had characteristics that allowed recalibration without patient removal from the imaging system.